Fuse



Cet. 26, 1954 N. B. WALES, JR

FUSE

2 Sheets-Sheet l Filed June 14, 1946 WR Rm! Nhen-'nel l WEES TT'.

ct. 26, 1954 N, B, WALES, JR 2,692,557

FUSE Filed June 14, 1946 2 Sheets-Sheet 2 Naihanel EEEE Jl"- @12 MMMJJ/MM www@ Patented Oct. 26, 1954 UNITED STATES PATENT OFFICE FUSE Application June 14, 1946, serial No. 676,600

(ci. 1oz-7s) '7 Claims. -1

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a base detonating fuse designed for use in bazooka type rockets.

The primary object of the invention is to increase the sensitivity of the fuse upon graze-impact of the projectile.

Another object is to provide a fuse perfectly safe in handling and shipment and safe in the bore of the launcher by reason of employing a bore-safe pin requiring a high setback for its release.

In the drawings illustrating the invention:

Figure l is a side elevation of the fuse plug; the rocket head attached thereto, and a portion of the rocket stabilizing tube.

Figure 2 is a cross-section taken on the line 2-2 of Figure l Figure 3 is a horizontal section taken on the line 3 3 of Figure 1;

Figure 4 is a view similar to Figure 3 showing the firing pin assembly in setback position at the moment of setback;

Figure 5 is a similar View showing the assembly after the cessation of the setback forces;

Figure 6 is a sectional view showing the movable parts in non-grazing-impact position;

Figure '7 is a view intended to show the position the hammer is capable of assuming upon graze-impact;

Figure 8 is a fragmental section showing means which may be employed for locking the firing pin against rotational creeping relative to the sleeve in order that the safety band with its pull pin may be accurately replaced to restore the fuse to safe condition in case the rocket is manually removed from the launcher;

Figure 9 is a perspective View of a cup-shaped firing pin member employed in the arrangement shown in Figure 8.

Referring to the drawings, the numeral l designates the rocket head; 2 the fuse plug; and 3 a fragment of the rocket stabilizing tube.

The fuse body or plug 2 is provided with a longitudinal bore Il internally threaded at its forward end as indicated at 5 for the reception of the external threads of a booster charge plug 6 containing a booster Ycharge 1 adjacent the explosive charge 8 in the rocket head, the head being threadedly attached to the plug 6 as indicated at 9i. The rear end of the fuse body or plug is provided with threads 5 for the reception of the threads of the stabilizing tube 3, as usual.

Booster charge plug 5 has a circular recess lli in its inner end to receive the reduced rear end of a detonator block Il containing adetonator I2 communicating with the interior of the bore of the fuse plug through a short passage I3 for the passage of the striker of the firing pin, which will presently be described.

A pocket lll is provided in the wall of the plug 2 having an opening l5 for the passage of boresafe or expellable pin IB which extends into and substantially spans the bore e of the fuse plug. Pin I6 carries at its upper end an inverted cup Il between the inside of which and the lloor of the pocket Iii is a spiral spring Il normally urging the pin out of the bore. At a point on the pin where it intersects the bore ll it is provided with a transverse slot I8 for the reception of a portion of the forward edge of setback sleeve I9 slidable in the bore. In the inner end of the pin there is an elongated narrow open end recess 2B, normally, or when the fuse is in unarmed condition, is occupied by the striker 2| on the forward end of the cup-shaped ringpin 22 slidably supported in the sleeve i9 and also in the bore l of the fuse plug. The firing pin member is provided at its rear end with an outwardly extending annular flange 23 which rides on the inner periphery of the bore d, and be tween the flange and the rear edge of the setback sleeve there is interposed an appropriately pretensioned spring 24 normally urging the setback sleeve forward and holding its'front edge in the transverse slot IS in the pin i6.

The diameter of the bore 4 is reduced at its rear end to form a shoulder 25 normally en-A gaged by an annular ilange 26 of a hammer 2l whose main body portion is tapered or in the shape of a truncated cone, the flange of the hammer being held squarely-and rmly against the shoulder 25 by the reaction of the spring 2e acting through the firing pin member.- The body of the hammer is of considerable-weightY and is normally centrally located in the bore i with its centerof gravity located in its tapered section forward of the flange so that the hammer will be deilected from its central position on the axis of the fuse by graze-impact, in which event the flange of the hammer will drive the ring pin forward to cause the striker to contact the detonator in the detonator block I I (see Figure '7 As a safety means for handling the fuse and in shipment, and as means for protecting the fuse against the weather, I preferably provide a band 28 formed of two sections hinged at 29. and providedgatth'endsfopposite the hinge with eyes ZSfofr the reception of conventional buckle members 30 to secure the band to the fuse. One section of the band is formed with a circular portion 3i shaped to form a dome 32 which is positioned over the safety pin I6. The circular portion 3l carries, adjacentthe dome, asafety pull pin 33 which extends through an aperture in the wall of the fuse and intoI normally registering holes 34 and 34 respectively in the sleeve I9 and firing pin member 22,` as shownl'inFigure 3. As shown in this figure, one section of the band hugs the fuse body while the other is spaced therefrom. In this space and; surrounding the inverted cup II is afwasher 35 of compressible material designed to surround and seal the opening through the fuse body against weather andtoi protect the safety pin I6.

As intimated, it may be desirable, after having removed the safety band and its safety pull pin and placed the rocket in the launcher, to remove the rocket from the launcher and replace the band and'safety pull pin, against the time the rocket is again loaded in the launcher. In these circumstances; as it may be that there has been so-me slight rotational movement of the firing pin member relative to the sleeve I9, taking the pin holes '3d' and 34 out of registry and making it diliicult jto accurately replace the safety band. To meet l this contingency, in one form, that shown in Figures 6 and 7, I provide an elongated slot 3S in the firing p-in member to receive the head 3l of a rivet 38 carried by the Sleeve. This slot also receivesthe lower end ofthe safety pull pin, the slot being suiciently long to -permit the necessary relative longitudinal movement betweenthe seeve and i-lring pin member.

Operation-The normal unarmed positions of the fuse parts are shown in Figure 3'. The safety band is first removed from the fuse. On ring the rocket the acceleration causes sleeve I9 to move rearwardly against the` pressure of the spring 2li, thus releasing the expellable pin which i f.

is ejected by its spring as the rocket leaves the bore of the launcherv and at the time acceleration ceases. Spring 24 then forcessleeve Iii forward against the detonator block II, and the reaction of the spring holds'firing pin member in fully retracted position ready for iiring while the rocket is in free flight and at the same time holding the hammer 21 in position with its fiange against the shoulder 25 thereby maintaining the tapered section of the hammer centrally with the axis of the fuse. Upon impact of the rocket head with the target, the deceleration of the fuse body causes the hammer 2l' to move forward'and drive the firing pin into the detonator. A graze-impact on the target'which causesangular acceleration ofthe fuse and rocket will cause the hammer, whose center of gravity Vis located in its tapered section forward of its flange, to deflect from its central position on the-axis f the fuse and by so deecting'the flange of'thehan'i- 4 mer will drive the firing pin member forward to cause the firing pin to contact the detonator.

I claim:

1. A base detonating fuse for projectiles, comprising a body having a bore therein close at its rear end, a detonator block at its forward end, a detonator in said block, a hammer formed with a tapering forward section and an annular flange at its rear end, the center of gravity of the hammer being located in the section forward of said iiange, a cup-shaped firing pin member slidable in the bore and providedwith a'striker for contacting said detonator, said firing pin member surrounding the tapered portion of the ham- 'mer with its rear end in engagement with the flange of said hammer, a sleeve slidable in the V'bore and surrounding the ring pin member, resilient means interposed between the sleeve and the firing pin member normally urging the sleeve forward while viirging the firing pin rearward, said resilient means through the instrumentality of the ring pin' member serving to center the hammer in said ringupin member, expellable means normally positioned between the detonator block and the iiring pin member and sleeve normally blocking said member and sleeve from movement toward the detonator, and means for expediting the expulsion o f said expellable means, said hammer being constructed and arranged to drive ,the firing pin member forward upon impact toggignite thedetonator. Y

2,.' The invention `of claim 1 vcharacterized in that the expellable means comprises a pin interposedA between the detonator block and firing pin member and sleeve andhaving a slot therein engaged by the sleeve to lock the pin'in position in ,the fuse- 3. The invention of claim 1 characterized in that 4the ringpin member and sleeve are provided with normallyv registering holes and the wall of the fuse body is provided with an aperture in v'which there vis a safety pull pin entering said holes andA normally preventing independent longitudinal movement between the sleeve and the ringrpin member and serving as additional means for normally holding said sleeve in engagement with the expellable means to lock said expellable means in the fuse.

4. The invention of claim 1 characterized in that there is means carried partly by the firing pin member-and partly by the-sleeve for preventing rotation of the firingpin member relative to the sleeve. I i A 5 A base 4detoriating fuse for projectiles oomprising a body having an axial 'bore therein, a detonator inthe forward end thereof, a hammer formed witha tapering forward section and anwa'nnularfange at-itsrear end, a cylindrical firing-pin member slidable in said bore and pro.- vided withafstrike'r for engaging said detonator, said firing pin member surrounding. the tapered portion of `the hammer with Vits rear end in engagement 'with the flange olf said hammer, a sleeve slidable in the said bore and embracing said yfiring pin member, resilient means interand having a slot formed therein engaged by the said sleeve to lock the pin in position.

7. A base detonating fuse for projectiles comprising a body having a bore therein, a detonator at the forward end of said bore, a hammer 5 formed with a tapering forward section and a flange at its rear end, a cylindrical firing pin member slidable in the bore and provided with a striker for contacting said detonator, said ring pin member embracing said hammer, a slidable sleeve surrounding said ring pin member, a spring normally urging the said sleeve and the said ring pin member apart, a pin interposed between the said detonator and the said ring pin member and normally blocking such iring 15 pin member from movement toward the detonator, and means for expediting the expulsion of the said pin.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,318,098 Midgley Oct. 7, 1919 1,393,585 Sutton Oct. 11, 1921 1,481,635 Councilman Jan. 22, 1924 2,118,062 Woodberry May 24, 1938 FOREIGN PATENTS Number Country Date 502,796 France Feb. 27, 1920 710,621 Germany Sept. 18, 1941 

